Yeah I noticed this game was a bit more picky about sound issues than the other sierra games. Running Dosbox, my game would hang near the very start of the game (after intro) where the robot zooms by and you hear the ship's computer voice talk about the self destruct sequence. I can still exist the game, but the game itself seems to be permantly waiting.
Anyway I solved it by making dosbox emulate the older soundblaster pro card rather than the default soundblaster 16 card (which is the better more advanced card but for whatever reason, this game has issues with it).
I also had to run the install program from the space quest directory and set soundcard to soundblaster rather than the default roland option. WHich is sad because I use have the roland with soundblaster combo in my old 386pc machine and that rocked. The superior Roland midi music, which Sierra took advantage of, sounded great.
So basically the steps you've got to do:
1) in dosbox, have dosbox write out a conf file using the -writeconf to/my/path/dosbox.conf option, like
-writeconf c:\oldgames\dosbox.conf
See this link to read about it in detail.
dosbox faq on config
2) edit the dosbox.conf file you've created (or whatever you called it) in your text editor. Look for the "[sblaster]" section and change "type=sb16" to "type=sbpro1"
Save your conf file
Read
this (dosbox configuration files) and
this (soundblaster section) for more info about conf (configuration files).
3) start dosbox (or restart if you had it running) with your conf file by using the -conf to\my\path option, like:
dosbox -conf c:\oldgames\dosbox.conf
4) finally if you haven't already, navigate to your space quest 1 vga directory and run the install program, by typing "install" and then change the soundcard setting to soundblaster and save your changes and exit the program
5) run space quest. BTW, there seems to be a missing bat file in the zip download for this game on this site, so you'll have to run space quest by executing the "SCIDHUV.EXE" executable by typing in "SCIDHUV" at the command prompt instead of "sierra" or "sq1" like you'd normally expect. You can make your own bat file if you want since they are just simply text files, but I won't go into that here.
This worked with me and I didn't have to alter or mess with different soundblaster drivers (those *.drv files).